NAME: Yersinia pseudotuberculosis
SYNONYM OR CROSS REFERENCE: Yersiniosis, pseudotuberculosis (yersinia).
CHARACTERISTICS: Yersinia pseudotuberculosis is a gram negative, facultatively anaerobic, non spore-forming, coccoid bacillus of the genus Yersinia, of the family Enterobacteriaceae Footnote 1, Footnote 2. It is motile at room temperature but non-motile at 37 ºC Footnote 1. Members of this species usually range from 0.5-0.8 µm by 1-3 µm in size Footnote 1. Of 15 different of serotypes, (8 thermostable groups (I-VIII) with nine subtypes and 5 thermolabile H antigens (a-e)) the O:1 serotype is responsible for 60-70% of human pseudotuberculosis (yersinia) cases Footnote 1-Footnote 3. The serogroups are determined by the antigens present in the bacterium Footnote 2.
PATHOGENICITY/TOXICITY: Yersinia pseudotuberculosis is a rare cause of acute enteric disease with symptoms such as acute mesenteric lymphadenitis and gastroenteritis associated with abdominal pain and fever (diarrhea is unusual). Footnote 3-Footnote 5. One to 3 weeks after the acute phase of the disease, post-infectious complications can occur, such as reactive arthritis and erythema nodosum. The arthritic phase of the disease can last up to 6 months Footnote 3. Other complications include lesions to lymph nodes, spleen and liver, as well as septicaemia in immunocompromised patients Footnote 1, Footnote 4. The disease is most common in children and young adults and immunocompromised individuals are at greater risk of severe disease or death Footnote 1, Footnote 5.
EPIDEMIOLOGY: Worldwide distribution, and most common in younger patients Footnote 2, Footnote 3. In an outbreak in Finland due to contaminated lettuce, the median age of patients was 19 years old Footnote 6. The number of infections peaks in late fall to spring and epidemics have been caused by contaminated food or water Footnote 3, Footnote 4.
INFECTIOUS DOSE: The infectious dose is of 108 bacteria or more orally Footnote 5.
MODE OF TRANSMISSION: The disease can be spread from human-to-human or animal-to-human primarily by fecal-oral transmission Footnote 4. Consumption of contaminated foods (infections by pasteurized milk, chocolate milk, tofu, beans and home slaughtered pork have been reported) and water, as well as contact with infectious soil, can cause an infection Footnote 1, Footnote 3, Footnote 4.
COMMUNICABILITY: The disease can be spread from human-to-human and can still be present in stool weeks after the clinical symptoms have ceased Footnote 7.
ZOONOSIS: The disease can be spread from animals to humans by contact with infected animals and their feces Footnote 4.
DRUG SUSCEPTIBILITY: Susceptible to ampicillin, third generation cephalosporins, aminoglycosides, tetracyclines, and chlorampheinicol Footnote 4.
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 2-5% phenol, 1% sodium hypochlorite, 70% ethanol, 4% formaldehyde, 2% glutaraldehyde, 2% peracetic acid, 3-6% hydrogen peroxide and 0.16% iodine Footnote 8, Footnote 9.
PHYSICAL INACTIVATION: Bacteria are sensitive to moist heat (121 ºC for at least 12 minutes) and dry heat (170 ºC for 1 hour) Footnote 10.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: In some cases, antibiotics may be needed although infections by this bacterium are usually self limiting Footnote 13.
LABORATORY-ACQUIRED INFECTIONS: None have been reported to date.
SOURCES/SPECIMENS: The bacterium can be found in stool, blood or lymph node tissues Footnote 1.
PRIMARY HAZARDS: Accidental parenteral inoculation is always a risk when working with pathogens and ingestion of the infectious agent (via contaminated hands) is a hazard for laboratory personnel working with enteric pathogens Footnote 5.
SPECIAL HAZARDS: Contact with infected animals Footnote 4.
RISK GROUP CLASSIFICATION: Risk group 2 Footnote 14.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 15, Footnote 16.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 15.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 15.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism by autoclave, chemical disinfection, gamma irradiation, or incineration before disposing.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: December 2011
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2011